Re: Scheme void function problems

[David Nalesnik]

On Wed, Mar 25, 2015 at 2:31 PM, David Nalesnik <address@hidden> wrote:

On Wed, Mar 25, 2015 at 2:27 PM, David Nalesnik <address@hidden> wrote:

Hi Simon,

The problem with the last invocation is this.  LilyPond considers whether the first argument you give it--"deutsch"--is a symbol.  It isn't, so it uses 'general.  Then, it looks further on for a suitable value for 'language', not for 'channel'. 

Sorry, that last should read "...a suitable value for 'language', beyond 'deutsch'."

How about this?  A bit contrived maybe...(A better solution eagerly awaited!)

%%%%

\version "2.19.16"

#(define output-language '())

language =

#(define-music-function (parser location channel language)

   (string-or-symbol? scheme?)

   (_i "Define languages for input (i.e. set note names for @var{language}),

output (i.e. display tagline and table of contents in @var{language}), or both.")

   (let* ((return (if (ly:music? language) language #{ #}))

          (language (if (string? language) language channel))

          (channel (if (string? channel) 'general channel)))

   

     (if (not (eq? channel 'output))

         (note-names-language parser language))

     (if (not (eq? channel 'input))

         (set! output-language (string->symbol language)))

     return

     ))

\language general "deutsch"

%\language "deutsch"

#(newline)

{

  c

}

%%%

David